Buckle

ABSTRACT

There is provided a buckle. A pair of vertical bars and a horizontal bar of a string attachment part of a female member are located below an upper surface of an operation portion. A coupling wall extending downwards from a front side of an upper plate of a female member main body and coupled to at least one of a lower plate of the female member main body and the string attachment part is provided. The operation portion is positioned at an outside with respect to an outer edge of the coupling wall at a state where engagement between an engaging portions of the male member and the engaged portions of the female member is released.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority of Japanese Patent Application No. 2015-001388, filed on Mar. 25, 2015 and entitled “Buckle”, the entire contents of which are hereby incorporated by reference.

TECHNICAL FIELD

The disclosure relates to a buckle having an excellent release operability of releasing engagement between a male member and a female member.

BACKGROUND

A buckle disclosed in Patent Document 1 has a male member and a female member to which the male member can be inserted and engaged. The male member has an elastically deformable insertion piece, an engaged face formed on the insertion piece and an operation portion configured to elastically deform the insertion piece. The female member has an insertion hole configured to insert the insertion piece of the male member therethrough, an engaging face configured to be engaged with the engaged face of the insertion piece and to engage the male member to the female member, and an opening that exposes the operation portion of the male member to an outer surface when the engaging face is engaged to the engaged face. Also, the male member and the female member have a string attachment part to which a string-shaped member can be attached. The engagement between the engaged face of the male member and the engaging face of the female member is released by pressing the operation portion of the male member exposed through the opening with sandwiching the same from both sides.

Patent Document 1: Japanese Patent Application Publication No. 2004-065773A

According to the buckle disclosed in Patent Document 1, a width of the string attachment part of the female member is substantially the same as a width of the operation portion when the engaging face is engaged to the engaged face, and a thickness of the string attachment part is thicker than the operation portion. For this reason, when releasing the engagement between the engaged face and the engaging face by pressing the operation portion of the male member exposed through the opening of the female member with sandwiching the same from both sides, fingers interfere with the string attachment part, so that the release may be difficult. Therefore, it is needed to improve a release operability, particularly, a release operability with gloves on in the winter, for example.

SUMMARY

It is therefore an object of the disclosure to provide a buckle having an excellent release operability of easily releasing engagement between a male member and a female member by enabling an operation portion to be easily gripped.

According to an aspect of the embodiments of the present invention, there is provided a buckle comprising: a male member; and a female member to which the male member is to be inserted and engaged, wherein the male member includes a male member main body, a pair of leg parts protruding from the male member main body and being elastically deformable in a direction of coming close to or separating from each other, and engaging portions respectively provided in the leg parts and being engageable to the female member, wherein the female member includes: a female member main body having an upper plate, a lower plate, an insertion hole, which is formed between the upper plate and the lower plate and configured to insert the pair of leg parts of the male member therethrough, and engaged portions configured to be engaged with the engaging portions of the pair of leg parts; and a string attachment part connected to the female member main body in front of an insertion direction of the male member and having a string attachment hole to which a string-shaped member is to be inserted and engaged, wherein the pair of leg parts of the male member or the female member is provided with an operation portion configured to elastically deform the pair of leg parts to release engagement between the engaging portions and the engaged portions, wherein the string attachment part has at least a pair of vertical bars extending in the insertion direction of the male member and a horizontal bar connecting the pair of vertical bars, wherein the pair of vertical bars and the horizontal bar are located below an upper surface of the operation portion, wherein a coupling wall extending downwards from a front side of the upper plate and coupled to at least one of the lower plate and the string attachment part is provided, and wherein the operation portion is positioned at an outside in a width direction with respect to an outer edge of the coupling wall in the width direction at a state where engagement between the engaging portions and the engaged portions is released. Therefore, when releasing the engagement between the male member and the female member, it is possible to easily grip the operation portion without interfering with the string attachment part and the coupling wall, thereby improving the release operability.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIG. 1 is a perspective view depicting an engaged state of a buckle according to a first illustrative embodiment of the disclosure;

FIG. 2 is a perspective view depicting a male member and a female member at an engagement-released state of the buckle of FIG. 1;

FIG. 3A is a plan view of the female member shown in FIG. 2, FIG. 3B is a side view, FIG. 3C is a front view and FIG. 3D is a sectional view taken along an line of FIG. 3A;

FIG. 4A is a plan view of the male member and the female member at the engaged state, FIG. 4B is a side view, and FIG. 4C is a sectional view taken along an IV-IV line of FIG. 4A;

FIG. 5 is a perspective view depicting an engaged state of a buckle according to a second illustrative embodiment of the disclosure;

FIG. 6 is a perspective view depicting a male member and a female member at an engagement-released state of the buckle of FIG. 5;

FIG. 7A is a plan view of the female member shown in FIG. 6, FIG. 7B is a side view, FIG. 7C is a front view and FIG. 7D is a sectional view taken along a VII-VII line of FIG. 7A;

FIG. 8A is a plan view of the male member and the female member at the engaged state, FIG. 8B is a side view, and FIG. 8C is a sectional view taken along a VIII-VIII line of FIG. 8A;

FIG. 9 is a perspective view depicting an engaged state of a buckle according to a third illustrative embodiment of the disclosure;

FIG. 10 is a perspective view depicting a male member and a female member at an engagement-released state of the buckle of FIG. 9;

FIG. 11A is a plan view of the female member shown in FIG. 10, FIG. 11B is a side view, FIG. 11C is a front view and FIG. 11D is a sectional view taken along a XI-XI line of FIG. 11A; and

FIG. 12A is a plan view of the male member and the female member at the engaged state, FIG. 12B is a side view, and FIG. 12C is a sectional view taken along a XII-XII line of FIG. 12A.

DETAILED DESCRIPTION

Hereinafter, respective illustrative embodiments of a buckle of the disclosure will be described in detail with reference to the drawings. In below descriptions, regarding the buckle, an upper side indicates a front side with respect to the drawing sheets of FIGS. 4A, 8A and 12A, for example, and a lower side indicates a rear side with respect to the drawing sheets of FIGS. 4A, 8A and 12A. Also, a left-right direction and a front-rear direction are defined, as seen from an insertion direction of a male member. A right side indicates a left side with respect to the drawing sheets of FIGS. 4A, 8A and 12A, a left side indicates a right side with respect to the drawing sheets of FIGS. 4A, 8A and 12A, a front side indicates the insertion direction of the male member (the lower side in FIGS. 4A, 8A and 12A), and a rear side indicates a reverse direction to the insertion direction of the male member (the upper side in FIGS. 4A, 8A and 12A). The front side is also referred to as the front side in the insertion direction, and the left-right direction of the buckle is also referred to as a width direction.

First Illustrative Embodiment

As shown in FIGS. 1 to 4, a buckle 10 of the first illustrative embodiment is to couple and separate end portions of string-shaped members 11, 12, and has a male member 20 and a female member 40 to which the male member 20 can be inserted and engaged. The male member 20 and the female member 40 are formed of a synthetic resin by injection molding. Also, the materials of the male member 20 and the female member 40 are not limited to the synthetic resin and may be metals.

As shown in FIG. 2, the male member 20 has a male member main body 21, a pair of leg parts 22 protruding forwards from both sides of the male member main body 21 in the width direction in parallel with each other, and a protrusion 23 protruding forwards between the leg parts 22.

The male member main body 21 has a substantially rectangular shape, which is long in the width direction, and is formed at its central portion with a string attachment part 25 having a string attachment hole 24 to which an end portion of the string-shaped member 11 can be inserted and engaged. The string attachment hole 24 is provided in the middle thereof with a coupling rod 26 extending in the width direction. By the coupling rod 26, the string attachment hole 24 is divided into two string attachment holes 24A, 24B, so that a length of the string-shaped member 11 can be adjusted.

The pair of leg parts 22 is elastically deformable in a direction of coming close to or separating from each other (in a left-right direction orthogonal to an insertion direction of the male member 20). The leg parts 22 have thin elastic arm portions 22A integrally formed at both sides of the male member main body 21 in the left-right direction and bulging portions 22B bulging from leading end portions of the elastic arm portions 22A.

An outer side of the bulging portion 22B is formed with an insertion guide face 27 convex outwardly in the width direction, an operation portion 28 gently curved continuously outwardly from the insertion guide face 27 and an engaging portion 29 bent inwardly from the operation portion 28, in corresponding order from the leading end portion 22 a towards a base end portion.

The protrusion 23 is formed to protrude from inner parts of the male member main body 21, which is located inner than outer parts of the male member main body 21 where the pair of leg parts 22 are provided, in the protruding direction (the front side) of the leg parts 22, and to couple the inner parts each other. That is, the protrusion 23 has a substantial V-shape gradually protruding from both end portions of the male member main body 21 in the width direction towards a central portion in the width direction. At a leading end portion of the protrusion 23, which is an apex of the substantial V-shape, one guide piece 30 is provided to protrude in parallel with the pair of leg parts 22.

The female member 40 has a female member main body 45 formed to have a flat cylindrical shape and having an upper plate 41, a lower plate 42, and a pair of sidewalls 43, 43 formed at both sides of the upper and lower plates 41, 42 in the width direction. The female member main body 45 has an insertion hole 44 (refer to FIG. 3D) defined by the upper plate 41, the lower plate 42 and the pair of sidewalls 43, 43. In the insertion hole 44, the pair of leg parts 22 of the male member 20 can be inserted. Also, the female member 40 is formed with a coupling wall 54 extending downwards from a front side of the upper plate 41 and coupled to the lower plate 42 and coupling bars 51, 51 of a string attachment part 49 (which will be described later).

The pair of sidewalls 43, 43 is formed only at portions close to rear ends of the upper and lower plates 41, 42, and a pair of openings 46 is formed in front of the pair of sidewalls 43, 43 and at both sides of the upper plate 41 and the lower plate 42 in the width direction by end portions of the upper and lower plates 41, 42 in the width direction, front end portions of the sidewalls 43, 43 and the coupling wall 54.

The openings 46 are notched to have a concave curve shape towards an inner side of the upper plate 41 and the lower plate 42 in the width direction. When the leg parts 22 are inserted into the insertion hole 44, the operation portions 28 of the male member 20 are exposed through the openings 46. Also, the front end portions of the pair of sidewalls 43, 43, which are rear ends of the openings 46, are formed with parts to be engaged 47 that are engageable with the engaging portions 29 of the pair of leg parts 22.

Inner surfaces of the pair of sidewalls 43, 43 become narrower towards the front side, i.e., are inwardly inclined. Thereby, when the leg parts 22 are inserted into the insertion hole 44, the insertion guide faces 27 contact the inner surfaces of the pair of sidewalls 43, 43 to elastically deform the pair of leg parts 22 in a direction (inward direction) substantially orthogonal to the insertion direction.

When the engaging portions 29 of the pair of leg parts 22 are inserted to the positions of the engaged portions 47 of the female member 40, the pair of leg parts 22 is opened by the elastic force and the engaging portions 29 and the engaged portions 47 are engaged, so that the male member 20 is engaged to the female member 40.

The lower plate 42 of the female member 40 is integrally formed at its front side with the string attachment part 49 having a string attachment hole 48 to which an end portion of the string-shaped member 12 can be inserted and engaged. Specifically, the string attachment part 49 has a pair of coupling bars 51, 51 extending from the lower plate 42 towards both sides in the width direction, a pair of vertical bars 52, 52 extending forwards from the pair of coupling bars 51, 51 and a horizontal bar 53 connecting leading end portions of the pair of vertical bars 52, 52. The string attachment hole 48 is defined by the coupling wall 54, the pair of coupling bars 51, 51, the pair of vertical bars 52, 52 and the horizontal bar 53.

Also, as shown in FIG. 4B, the string attachment part 49, i.e., the pair of coupling bars 51, 51, the pair of vertical bars 52, 52 and the horizontal bar 53 are all located below upper surfaces 28 a of the operation portions 28.

Specifically, in the first illustrative embodiment, as shown in FIG. 4B, the string attachment part 49 is located below a center C of the operation portion 28 in a thickness direction, and is also offset downwards with respect to an intermediate portion Ll of the upper plate 41 and the lower plate 42 in a height direction, as shown in FIG. 3D. For this reason, a lower surface 49 a of the string attachment part 49 is formed below a lower surface 42 a of the lower plate 42.

Meanwhile, in the first illustrative embodiment, the upper surface 28 a of the operation portion 28 is located below an upper surface 41 a of the upper plate 41.

Also, the lower surface 49 a of the string attachment part 49 is configured by a lower surfaces of the vertical bars 52.

The lower surface 42 a of the lower plate 42 has an inclined surface 42 a 1 inclined downwardly towards the lower surface 49 a of the string attachment part 49, and is configured to smoothly continue the lower surface 42 a of the lower plate 42 and the lower surface 49 a of the string attachment part 49.

The coupling wall 54 configured to couple the upper plate 41 and the lower plate 42 is located at an inner side in the width direction with respect to an outer edge 49 b of the string attachment part 49 in the width direction, and is gradually widened towards the lower plate 42, as shown in FIG. 3C, so that it is also coupled to the pair of coupling bars 51, 51. Thereby, the strength of the pair of coupling bars 51, 51 is reinforced.

In this way, since the height of the string attachment part 49 is lower than the upper surfaces 28 a of the operation portions 28 and the coupling wall 54 configured to couple the upper plate 41 and the lower plate 42 is located at the inner side in the width direction with respect to the outer edge 49 b of the string attachment part 49 in the width direction, an area (refer to a dashed-dotted line A) located above the string attachment part 49 and at an outside in the width direction with respect to the coupling wall 54 has a shape opening in the width direction from the openings 46 to the string attachment part 49, as shown in FIGS. 3A and 3C.

An intermediate portion of the coupling wall 54 in the width direction is formed with a recess portion 56. The string attachment hole 48 can widen a space of the male member 20 in the insertion direction by the recess portion 56, so that a string can easily pass through the string attachment hole 48.

In the below, engagement and engagement release between the male member 20 and the female member 40 are described. When the pair of leg parts 22 of the male member 20 is inserted into the insertion hole 44 of the female member 40, the insertion guide faces 27 of the pair of leg parts 22 are contacted to the inner surfaces of the pair of sidewalls 43, 43 inclined in the front-inner direction, so that the pair of leg parts is inserted with being inwardly elastically deformed. Then, when the engaging portions 29 of the pair of leg parts 22 and the engaged portions 47 of the female member 40 are matched each other, the pair of leg parts 22 is opened by the elastic force, the operation portions 28 of the pair of leg parts 22 are exposed through the openings 46 and the engaging portions 29 and the engaged portions 47 are engaged, so that the male member 20 is engaged to the female member 40, as shown in FIG. 4.

At the engaged state of the buckle, since the operation portions 28 are arranged at the inner sides in the width direction with respect to the outer edges 49 b of the string attachment part 49 in the width direction, as shown in FIG. 4A, a compact design in the width direction of the buckle 10 is made. That is, when a size between the operation portions 28 at the outermost edges in the width direction is denoted as P1 (refer to FIG. 4A) and a size between the outer edges 49 b of the string attachment part 49 in the width direction is denoted as S1 (refer to FIG. 3A), a design is made so as to be S1>P1.

Also, since the leading end portions 22 a of the pair of leg parts 22 overlap with the pair of coupling bars 51, 51 in the thickness direction (upper-lower direction), it is possible to shorten an entire length of the buckle 10, too.

Further, as shown in FIG. 4C, since the string attachment part 49 of the female member 40 is positioned on a line L passing through the lower surface 25 a of the string attachment part 25 of the male member 20 and being parallel with the insertion direction of the male member 20, as shown in FIG. 4C, even when the string-shaped members 11, 12 attached to the buckle 10 are pulled out in reverse directions, i.e., even when the tension is applied to the string-shaped members 11, 12, the rotation moment is not applied to the buckle 10, so that it is possible to stably bear the load.

When releasing the engagement between the male member 20 and the female member 40, it is possible to easily release the engagement by elastically deforming inwardly the operation portions 28 of the pair of leg parts 22 exposed through the openings 46 of the female member 40 with sandwiching the operation portions by fingers.

In particular, upon the release of the engagement between the male member 20 and the female member 40, when the operation portions 28 of the pair of leg parts 22 are sandwiched by the fingers, the inclination of the outer surfaces of the operation portions 28 relative to the insertion direction increases, as shown with the dashed-dotted line in FIG. 4A, and a high component force in a reverse direction (rearward direction) to the insertion direction of the male member 20 is applied to the male member 20. Therefore, when the engagement between the engaging portions 29 and the engaged portions 47 is released, the male member 20 can be easily separated from the female member 40 in combination with the operations of the inclined inner surfaces of the pair of sidewalls 43, 43, so that it is possible to easily perform the release operation with one hand.

Also, since the height of the string attachment part 49 is lower than the upper surfaces 28 a of the operation portions 28 and the operation portions 28 are positioned at the outside in the width direction with respect to the outer edges 54 a of the coupling wall 54 in the width direction, which is configured to couple the upper plate 41 and the lower plate 42 at a state where the engagement of the buckle is released, the fingers can be easily put on the operation portions 28 exposed through the openings 46 without interfering with the string attachment part 49 or the coupling wall 54. Therefore, it is possible to easily release the engagement with gloves on in the winter, for example. That is, when a size between the operation portions 28 at the outermost edges in the width direction is denoted as P2 at a state where the engagement is released (refer to FIG. 4A), a size between the outer edges 54 a in the width direction of the coupling wall 54 coupled to the upper plate 41 is denoted as S2 (refer to FIG. 3A) and a size between the outer edges 54 a in the width direction of the coupling wall 54 at the center C in the thickness direction of the operation portions 28 is denoted as S3 (refer to FIG. 3A), a design is made so as to be P2≧S3≧S2.

Also, as shown in FIGS. 3A and 3C, since the area A located above the string attachment part 49 and at an outside in the width direction with respect to the coupling wall 54 is opened widthwise from the openings 46 to the string attachment part 49, when pressing the operation portions 28 from the front of the female member main body 45 by the fingers, it is possible to suppress the string attachment part 49 from interfering with the fingers.

Particularly, according to the first illustrative embodiment, even at the engaged state of the buckle, the operation portions 28 are arranged at the inner sides in the width direction with respect to the outer edges 49 b of the string attachment part 49 (S1>P1) in the width direction, and even at the disengaged state of the buckle, the operation portions 28 are arranged at the inner sides in the width direction with respect to the outer edges 49 b of the string attachment part 49 (S1>P2) in the width direction. However, as described above, since the height of the string attachment part 49 is lower than the upper surfaces 28 a of the operation portions 28, it is possible to easily release the engagement with gripping the operation portions 28 without interfering with the string attachment part 49.

Also, since the leading end portions 22 a of the pair of leg parts 22 overlap with the pair of coupling bars 51, 51 in the thickness direction, it is possible to make the operation portions 28 larger, thereby further improving the release operability.

As described above, according to the buckle 10 of the first illustrative embodiment, the string attachment part 49 of the female member 40 has the pair of coupling bars 51, the pair of vertical bars 52 and the horizontal bar 53, the pair of coupling bars 51, the pair of vertical bars 52 and the horizontal bar 53 are located below the upper surfaces 28 a of the operation portions 28 of the female member main body 45, and the operation portions 28 are positioned at the outside in the width direction with respect to the outer edges 54 a of the coupling wall 54 of the female member main body 45 in the width direction at the state where the engagement of the buckle is released. Therefore, when releasing the engagement between the male member 20 and the female member 40, it is possible to easily grip the operation portions 28 without interfering with the string attachment part 49 and the coupling wall 54, thereby improving the release operability.

In particular, according to the first illustrative embodiment, even when the operation portions 28 are positioned at the inner sides in the width direction with respect to the outer edges 49 b of the string attachment part 49 in the width direction at the state where the engagement of the buckle is released, it is possible to secure the operability of the operation portions 28 without the operation portion 28 interfering with the string attachment part 49.

Further, according to the first illustrative embodiment, since the pair of coupling bars 51, the pair of vertical bars 52 and the horizontal bar 53 are located below the center C of the operation portions 28 in the thickness direction, it is possible to grip the operation portions 28 more securely without interfering with the string attachment part 49.

Also, at the state where the female member 40 and the male member 20 are engaged, the leading end portions 22 a of the leg parts 22 overlap with the coupling bars 51 in the thickness direction. Therefore, it is possible to shorten the entire length of the buckle 10, so that the buckle 10 can be made compact.

Also, the female member 40 has the coupling wall 54 configured to couple the upper plate 41, the lower plate 42 and the coupling bars 51 and to gradually widen towards the coupling bars 51. Therefore, it is possible to improve the strength of the coupling bars 51.

Also, the lower surface 49 a of the string attachment part 49 is located below the lower surface 42 a of the lower plate 42, and the lower surface 42 a of the lower plate 42 has the inclined surface 42 a 1 inclined downwardly towards the lower surface 49 a of the string attachment part 49. Thereby, it is possible to implement the arrangement of the string attachment part 49 enabling the favorable engagement-releasing operability, to secure the sufficient thickness of the string attachment part 49 and to prevent the stress from being concentrated between the string attachment part 49 and the lower plate 42.

Also, at the state where the female member 40 and the male member 20 are engaged, the pair of coupling bars 51, the pair of vertical bars 52 and the horizontal bar 53 of the female member 40 are arranged on the line L passing through the lower surface 25 a of the string attachment part 25 of the male member 20 and being parallel with the insertion direction of the male member 20. Therefore, when the string-shaped members 11, 12 inserted and engaged to the string attachment holes 24, 48 of the male member 20 and the female member 40 are pulled out, the directions of the forces of both the string-shaped member 11, 12 are located on the straight line. Thereby, it is possible to stabilize the buckle 10 without inclining the same.

Second Illustrative Embodiment

In the below, a buckle of a second illustrative embodiment is described with reference to FIGS. 5 to 8. A buckle 110 of the second illustrative embodiment has a male member 120 and a female member 140 to which the male member 120 can be inserted and engaged, like the buckle 10 of the first illustrative embodiment. The male member 120 and the female member 140 are formed of a synthetic resin by injection molding. The male member 120 and the female member 140 are not limited to the synthetic resin and may be formed of metals.

As shown in FIG. 6, the male member 120 has a male member main body 121, a pair of guide pieces 131 protruding from both sides of the male member main body 121 in the width direction (the direction orthogonal to the insertion direction of the male member 120) in parallel with each other in a longitudinal direction (the insertion direction of the male member 120), and a pair of leg parts 122 protruding from inner sides with respect to the guide pieces 131 in parallel with each other in the insertion direction of the male member 120 and being elastically deformable in a direction (a left-right direction) of coming close to or separating from each other.

The male member main body 121 has a substantially rectangular shape, which is long in the width direction, and is formed at its central portion with a string attachment part 125 having a string attachment hole 124 to which an end portion of the string-shaped member 11 can be inserted and engaged. The string attachment hole 124 is provided in the middle thereof with a coupling rod 133 extending in the width direction. By the coupling rod 133, the string attachment hole 124 is divided in two string attachment holes 124A, 124B, so that a length of the string-shaped member 11 can be adjusted.

The guide pieces 131 protrude in parallel with each other, and are respectively formed to have about a half length of the leg part 122.

Each of the pair of leg parts 122 has an elastic piece portion 122A extending straightly from the male member main body 121 in the insertion direction of the male member 120 and a guide portion 122B formed at a leading end portion of the elastic piece portion 122A. The elastic piece portion 122A is formed at its central portion with a recess 126, which penetrates upper and lower surfaces thereof and continues to the guide portion 122B. Thereby, the elastic piece portion 122A can be easily elastically deformable in the left-right direction. The guide portion 122B has an arc-shaped leading end portion, and an outer surface thereof is inclined outwardly from the leading end portion towards a base end portion to form an insertion guide face 127. An engaging portion 129 bent inwardly from the outer surface of the guide portion 122B is formed between the elastic piece portion 122A and the guide portion 122B. The engaging portion 129 can be engaged to a portion to be engaged 147 of the female member 140, which will be described later.

The female member 140 has a female member main body 145 formed to have a flat cylindrical shape and having an upper plate 141, a lower plate 142 and a pair of sidewalls 143, 143 formed at both sides of the upper and lower plates 141, 142 in the width direction. The female member main body 45 has an insertion hole 144 (refer to FIG. 7D) defined by the upper plate 141, the lower plate 142 and the pair of sidewalls 143. In the insertion hole 144, the pair of leg parts 122 of the male member 120 can be inserted. Also, the female member 140 is formed with a coupling wall 154 extending downwards from a front side of the upper plate 141 and coupled to the lower plate 142 and coupling bars 151, 151 of a string attachment part 149 (which will be described later).

In the insertion hole 144 of the female member main body 145, a partition wall 161 configured to couple the upper plate 141 and the lower plate 142 and extending in the front-rear direction of the female member main body 145 is integrally formed at a center in the left-right direction. A pair of contact walls 162 is provided in parallel with each other with the partition wall 161 being positioned therebetween. The contact wall 162 has a guide surface 163 configured to contact the insertion guide face 127 of the male member 120 and to elastically deform the leg parts 122 in the direction of coming close to each other, and a front end of the contact wall 162 is formed with a portion to be engaged 147 that can be engaged with the engaging portion 129 of the male member 120.

Also, the female member main body 145 is formed with operation portions 165 continuing from front ends of the sidewalls 143. Three sides of the operation portion 165 except for a coupler 165 a with the sidewall 143, i.e., upper, lower and front ends of the operation portion 165 are spaced from the female member main body 145 and are swingable in the left-right direction about the coupler 165 a serving as a support point.

The operation portion 165 further has an operation piece 165 b exposed on an outer surface and a pressing piece 165 c extending inwardly from a leading end portion of the operation piece 165 b in the width direction. When a leading end portion of the pressing piece 165 c faces the insertion guide face 127 of the male member 120 and the operation piece 165 b is inwardly pressed, the leading end portion of the pressing piece 165 c is contacted to the insertion guide face 127 of the male member 120 to elastically deform the leg part 122 inwardly. Thereby, the engagement between the engaging portions 129 of the male member 120 and the engaged portions 147 of the female member 140 is released.

A front end portion of the female member main body 145 is integrally formed with a string attachment part 149 having a string attachment hole 148 to which an end portion of the string-shaped member 12 can be inserted and engaged.

The string attachment part 149 has the pair of coupling bars 151, 151 extending from the lower plate 142 towards both sides in the width direction, a pair of vertical bars 152, 152 extending forwards from the pair of coupling bars 151, 151, and a horizontal bar 153 connecting leading end portions of the pair of vertical bars 152, 152. The string attachment hole 148 is defined by the coupling wall 154, the pair of coupling bars 151, 151, the pair of vertical bars 152, 152 and the horizontal bar 153.

As shown in FIGS. 7B and 7D, the string attachment part 149, i.e., the pair of coupling bars 151, 151, the pair of vertical bars 152, 152 and the horizontal bar 153 are all located below upper surfaces 165 d of the operation portions 165.

Specifically, also in the second illustrative embodiment, the string attachment part 149 is located below a center C of the operation portion 165 in a thickness direction, and is also offset downwards with respect to the intermediate portion Ll of the upper plate 141 and the lower plate 142 in a height direction, as shown in FIG. 7D. Further, a lower surface 149 a of the string attachment part 149 is formed below a lower surface 142 a of the lower plate 142.

Meanwhile, in the second illustrative embodiment, the upper surface 165 d of the operation portion 165 is located below an upper surface 141 a of the upper plate 141.

Also, the lower surface 149 a of the string attachment part 149 is configured by lower surfaces of the vertical bars 152.

Further, the lower surface 149 a of the string attachment part 149 has an inclined surface 149 a 1 inclined downwards within a range from the coupling bars 151 to rear parts of the vertical bars 152, and is configured to smoothly couple to the lower surface 142 a of the lower plate 142.

The coupling wall 154 configured to couple the upper plate 141 and the lower plate 142 is positioned at an inside in the width direction with respect to an outer edge 149 b of the string attachment part 149 in the width direction, and is gradually widened towards the lower plate 142, so that it is also coupled to the pair of coupling bars 151, 151, as shown in FIG. 7C. Thereby, the strength of the pair of coupling bars 151, 151 is reinforced.

In this way, since the height of the string attachment part 149 is lower than the upper surfaces 165 d of the operation portions 165 and the coupling wall 154 configured to couple the upper plate 141 and the lower plate 142 is located at the inner side in the width direction with respect to the outer edge 149 b of the string attachment part 149 in the width direction, an area (refer to a dashed-dotted line A) located above the string attachment part 149 and at an outside in the width direction with respect to the coupling wall 154 has a shape opening in the width direction, so that the upper parts of the operation portions 165 are exposed, as shown in FIGS. 7A and 7C.

In the below, engagement and engagement release between the male member 120 and the female member 140 are described. When the pair of leg parts 122 of the male member 120 is inserted into the insertion hole 144 of the female member 140, the insertion guide faces 127 of the pair of leg parts 122 are contacted to the guide surfaces 163 of the contact walls 162, so that the pair of leg parts 122 is inserted with being elastically deformed in the direction of coming close to each other.

Then, when the engaging portions 129 of the pair of leg parts 122 and the engaged portions 147 of the female member 40 are matched each other, the pair of leg parts 122 is opened by the elastic force, and the engaging portions 129 and the engaged portions 147 are engaged, so that the male member 120 is engaged to the female member 140, as shown in FIG. 8.

At this state, as shown in FIG. 8C, since the string attachment part 149 of the female member 140 is positioned on the line L passing through the lower surface 125 a of the string attachment part 125 of the male member 120 and being parallel with the insertion direction of the male member 20, even when the string-shaped members 11, 12 attached to the buckle 110 are pulled out in reverse directions, i.e., even when the tension is applied to the string-shaped members 11, 12, the rotation moment is not applied to the buckle 110, so that it is possible to stably bear the load.

When the operation portions 165 of the female member 140 are inwardly elastically deformed with being sandwiched by the fingers so as to release the engagement between the male member 120 and the female member 140, the pressing pieces 165 c are contacted to the insertion guide faces 127 of the male member 120, thereby inwardly elastically deforming the leg parts 122. Thereby, the engagement between the engaging portions 129 of the male member 120 and the engaged portions 147 of the female member 140 is released.

At this time, since the string attachment part 149 is located below the upper surfaces 165 d of the operation portions 165 and the operation portions 165 are positioned at the outside in the width direction with respect to the outer edges 154 a of the coupling wall 154 in the width direction at a state where the engagement of the buckle is released, the fingers can be easily put on the operation portions 165 of the female member 140 without interfering with the string attachment part 149 or the coupling wall 154, so that it is possible to easily release the engagement with gloves on in the winter, for example.

Therefore, like the buckle 110 of the second illustrative embodiment, even when the operation portions 165 are provided in the female member 140, it is possible to improve the release operability, like the buckle 10 of the first illustrative embodiment.

That is, also in the second illustrative embodiment, when a size between the operation portions 165 at the outermost edges in the width direction is denoted as P2 at a state where the engagement is released (refer to FIG. 8A), a size between the outer edges 154 a of the coupling wall 154 in the width direction, at parts coupled to the upper plate 141 is denoted as S2 (refer to FIG. 7A) and a size between the outer edges 154 a of the coupling wall 154 in the width direction at the center C of the operation portions 165 in the thickness direction is denoted as S3 (refer to FIG. 7A), a design is made so as to be P2>S3≧S2.

Also, in the second illustrative embodiment, at the engaged state of the buckle, the operation portions 165 are arranged at the outside in the width direction with respect to the outer edges 149 b of the string attachment part 149 in the width direction. However, at the disengaged state of the buckle, the operation portions 165 are arranged at the inner sides in the width direction with respect to the outer edges 149 b of the string attachment part 149 in the width direction, as shown with the dashed-dotted line in FIG. 8A. That is, when a size between the operation portions 165 at the outermost edges in the width direction is denoted as P1 (refer to FIG. 8A) and a size between the outer edges 49 b of the string attachment part 49 in the width direction is denoted as S1 (refer to FIG. 7A), a design is made to be P1>S1>P2.

At this time, as described above, since the height of the string attachment part 149 is lower than the upper surfaces 165 d of the operation portions 165, it is possible to grip the operation portions 165 without interfering with the string attachment part 149, thereby easily releasing the engagement.

The other operational effects are the same as the buckle 10 of the first illustrative embodiment.

Third Illustrative Embodiment

In the below, a buckle of a third illustrative embodiment is described with reference to FIGS. 9 to 12. A buckle 210 of the third illustrative embodiment has a male member 220 and a female member 240 to which the male member 220 can be inserted and engaged, like the buckle 10 of the first illustrative embodiment. The male member 220 and the female member 240 are formed of a synthetic resin by injection molding. The male member 220 and the female member 240 are not limited to the synthetic resin and may be formed of metals.

The male member 220 has a male member main body 221, a pair of leg parts 222 protruding forwards from both sides of the male member main body 221 in the width direction in parallel with each other and being elastically deformable in a direction (a left-right direction orthogonal to the insertion direction of the male member 220) of coming close to or separating from each other and a protrusion 223 protruding forwards between the pair of leg parts 222.

The male member main body 221 has a substantially rectangular shape, which is long in the width direction, and is formed at its central portion with a string attachment part 225 having a string attachment hole 224 to which an end portion of the string-shaped member 11 can be inserted and engaged. The string attachment hole 224 is provided in the middle thereof with a coupling rod 226. By the coupling rod 226, the string attachment hole 224 is divided in two string attachment holes 224A, 224B, so that a length of the string-shaped member 11 can be adjusted.

Each of the pair of leg parts 222 has an outer leg piece 222A and an inner leg piece 222B being elastically deformable in the left-right direction and a leading end portion coupler 222C configured to couple leading end portions of the outer leg piece 222A and the inner leg piece 222B. The inner leg piece 222B is provided at an inner side with respect to the outer leg piece 222A.

Each of the outer leg pieces 222A extends straightly from each of both sides of the male member main body 221 in the insertion direction of the male member 220, slightly bulges outwards from an intermediate position towards the leading end portion, and forms an inwardly gentle arc. The inner leg piece 222B is bent from an intermediate portion of the protrusion 223 towards the leading end portion coupler 222C.

A surface and a backside of a leading end portion of the leading end portion coupler 222C are formed with a pair of engaging portions 229 protruding from the leading end portion coupler 222C in the upper-lower direction.

An outer surface of the outer leg piece 222A is formed with an insertion guide face 227 and an operation portion 228 in corresponding order from the leading end portion coupler 222C towards the male member main body 221, and the operation portion 228 has a thickness that is thicker than the insertion guide face 227 and is substantially the same as the male member main body 221.

The protrusion 223 protrudes from a side of the male member main body 221, from which the leg parts 222 protrude, towards the protruding direction (forward direction) of the leg parts 222. Specifically, the protrusion 223 has a substantial bow shape where it extends inwardly from both end portions of the male member main body 221 in the width direction, extends obliquely forwards and leading end portions are coupled.

At a substantial center of the protrusion 223, one guide piece 230 protrudes in parallel with the pair of leg parts 222. The male member main body of the guide piece 230 and the protrusion 223 are coupled to each other by ribs 230 a to reinforce the strength.

The female member 240 has a female member main body 245 formed to have a flat cylindrical shape and having an insertion hole 244, which is defined by an upper plate 241, a lower plate 242 and a pair of sidewalls 243 formed at both sides of the upper and lower plates 241, 242 in the width direction. The insertion hole 244 is formed to penetrate the female member main body 245 in the front-rear direction. Each sidewall 243 is formed at its center in the upper-lower direction with an opening 246 having a slit shape and extending in the front-rear direction over a substantially entire length of the sidewall 243. When the pair of leg parts 222 of the male member 220 is inserted into the opening 246, the male member 220 is inserted into the insertion hole 244.

In the insertion hole 244 of the female member main body 245, a pair of partition walls 261 configured to couple the upper plate 241 and the lower plate 242 and extending in the front-rear direction is integrally formed. That is, a rectangular cylinder portion 266 defined by the upper plate 241, the lower plate 242 and the pair of partition walls 261 and extending in the front-rear direction is formed at a center of the insertion hole 244. The rectangular cylinder portion 266 is formed to penetrate in the front-rear direction in the insertion hole 244. A rear end of each partition wall 261 has a U-shaped recess 261 a notched into a U shape.

Guide surfaces 263 configured to contact the insertion guide faces 227 of the male member 220 and to elastically deform the leg parts 222 in the direction of coming close to each other are formed at left and right sides in the insertion hole 244, and engaged portions 247 configured to be engaged with the engaging portions 229 of the male member 220 and to engage the male member 220 to the female member 240 are provided at the fronts of the guide surfaces 263.

The guide surface 263 and the portion to be engaged 247 are formed with recesses protruding downwards from a lower surface of the upper plate 241 and upwards from an upper surface of the lower plate 242 and continuing to an opening 246 having a slit shape in the same recess width as the opening 246. When the male member 220 is inserted into the female member 240, the leading end portion couplers 222C of the male member 220 are inserted into the corresponding recesses.

The female member 240 is formed with coupling walls 254 extending downwards from both sides of a front side of the upper plate 241 in the width direction and coupled to coupling bars 251, 251 of a string attachment part 249 (which will be described later). Also, shield parts 255 are suspended from the front side of the upper plate 241 to close the front of the engaging portions 229 of the male member 220 engaged to the engaged portions 247.

The other end (front end) of the female member main body 245 is provided with a string attachment part 249 having a string attachment hole 248 to which an end portion of the string-shaped member 12 can be inserted and engaged. The string attachment part 249 has a pair of vertical bars 252, 252 extending forwards from left and right ends of the lower plate 242 and a horizontal bar 253 connecting leading end portions of the pair of vertical bars 252, 252. The string attachment hole 248 is defined by front ends of the shield part 255 and the lower plate 242, the pair of vertical bars 252, 252, and the horizontal bar 253.

As shown in FIGS. 7B and 7D, the string attachment part 249, i.e., the pair of vertical bars 252, 252 and the horizontal bar 253 are all positioned below upper surfaces 228 a of the operation portions 228.

Specifically, also in the third illustrative embodiment, the string attachment part 249 is located below the center C of the operation portion 228 in the thickness direction, as shown in FIG. 12B, and is offset downwards with respect to the intermediate portion Ll of the upper plate 241 in the height direction and the lower plate 242, as shown in FIG. 11D. Further, a lower surface 249 a of the string attachment part 249 is formed below a lower surface 242 a of the lower plate 242.

Meanwhile, in the third illustrative embodiment, the upper surface 228 a of the operation portion 228 is located slightly below an upper surface 241 a of the upper plate 241.

Also, the lower surface 249 a of the string attachment part 249 is configured by lower surfaces of the vertical bars 252 and the horizontal bar 253.

Further, the lower surface 249 a of the string attachment part 249 has an inclined surface 249 a 1 inclined downwards at the rear part of the vertical bar 252 and is smoothly coupled to the lower surface 242 a of the lower plate 242.

Also, the coupling wall 254 configured to couple the upper plate 241 and the vertical bar 252 is positioned at an inner side in the width direction with respect to an outer edge 249 b of the string attachment part 249 in the width direction.

In this way, since the height of the string attachment part 249 is lower than the upper surface 228 a of the operation portion 228 and the coupling wall 254 configured to couple the upper plate 241 and the vertical bar 252 of the string attachment part 249 is located at the inner side in the width direction with respect to the outer edge 249 b of the string attachment part 249 in the width direction, an area (refer to a dashed-dotted line A) located above the string attachment part 249 and at an outside with respect to the coupling wall 254 in the width direction opens in the width direction, as shown in FIG. 11C.

In the below, engagement and engagement release between the male member 220 and the female member 240 are described. When the male member 220 is inserted into the insertion hole 244 of the female member 240 while inserting the pair of leg parts 222 of the male member 220 into the openings 246 of the sidewalls 243 and fitting the guide piece 230 into the rectangular cylinder portion 266, the insertion guide faces 227 formed at the leading end portions of the pair of leg parts 222 are contacted to the guide surfaces 263 of the female member 240, so that the pair of leg parts 222 is inwardly elastically deformed.

Therefore, when the engaging portions 229 of the leg parts 222 are inserted to positions beyond the engaged portions 247 of the female member 240, the leg parts 222 inwardly elastically deformed are elastically returned to the original states. Thereby, the engaging portions 229 of the leg parts 222 are engaged to the engaged portions 247 of the female member 240, so that the male member 220 is engaged to the female member 240.

At this state, since the string attachment part 249 of the female member 240 is positioned on the line L passing through a lower surface 232 a of a boundary frame 232 of the male member 220 and being parallel with the insertion direction of the male member 220, even when the string-shaped members 11, 12 attached to the buckle 210 are pulled out in the reverse directions, i.e., even when the tension is applied to the string-shaped members 11, 12, the rotation moment is not applied to the buckle 210, so that it is possible to stably bear the load.

When the operation portions 228 exposed outside through the openings 246 of the female member 240 are inwardly elastically deformed with being sandwiched by the fingers so as to release the engagement between the male member 220 and the female member 240, the engagement between the engaging portions 229 and the engaged portions 247 can be easily released.

At this time, since the string attachment part 249 is located below the upper surfaces 228 a of the operation portions 228 and the operation portions 228 are positioned at the outside in the width direction with respect to the outer edges 254 a of the coupling walls 254 in the width direction at a state where the engagement of the buckle is released, the fingers can be easily put on the operation portions 228 exposed through the openings 246 without interfering with the string attachment part 249 or the coupling walls 254. Therefore, it is possible to easily release the engagement with gloves on in the winter, for example.

Therefore, like the buckle 200 of the third illustrative embodiment, even when the engaging portions 229 of the male member 220 are provided in the leading end portions of the leg parts 222 and the engaged portions 247 of the female member 240 are provided at the front side of the female member main body 245, it is possible to improve the release operability, like the buckle 10 of the first illustrative embodiment.

That is, also in the third illustrative embodiment, when a size between the operation portions 228 at the outermost edges in the width direction is denoted as P2 at a state where the engagement is released (refer to FIG. 12A), a size between the outer edges 254 a of the coupling walls 254 in the width direction, at parts coupled to the upper plate 241 is denoted as S2 (refer to FIG. 11A) and a size between the outer edges 254 a of the coupling walls 254 in the width direction, at the center C of the operation portions 228 in the thickness direction is denoted as S3 (refer to FIG. 11A), a design is made so as to be P2>S3≧S2.

Also, in the third illustrative embodiment, the operation portions 228 are positioned at the outside in the width direction with respect to the outer edges 249 b of the string attachment part 249 in the width direction at a state where the buckle is engaged. However, as shown with the dashed-dotted line in FIG. 12A, the operation portions 228 are positioned at the inner sides in the width direction with respect to the outer edges 249 b of the string attachment part 249 in the width direction at a state where the engagement of the buckle is released. That is, when a size between the operation portions 228 at the outermost edges in the width direction is denoted as P1 (refer to FIG. 12A) and a size between the outer edges 249 b of the string attachment part 249 in the width direction is denoted as S1 (refer to FIG. 11A), a design is made to be P1>S1>P2.

At this time, as described above, since the height of the string attachment part 249 is lower than the upper surfaces 228 a of the operation portions 228, it is possible to easily release the engagement with gripping the operation portions 228 without interfering with the string attachment part 249.

The disclosure is not limited to the above illustrative embodiments, and can be appropriately changed without departing from the gist of the disclosure.

For example, in the above illustrative embodiments, the insertion hole 44, 144, 244 of the female member 40, 140, 240 is defined by the upper plate 41, 141, 241, the lower plate 42, 142, 242 and the pair of sidewalls 43, 143, 243. However, the insertion hole of the disclosure is not limited thereto and may be formed between the upper plate 41, 141, 241 and the lower plate 42, 142, 242.

Also, in the above illustrative embodiments, the upper surface 28 a, 165 d, 228 a of the operation portion 28, 165, 228 is located below the upper surface 41 a, 141 a, 241 a of the upper plate 41, 141, 241. However, when the operation portion 165, 228 is provided in the male member 120, 220, the upper surface of the operation portion may be configured to be substantially flush with the upper surface 141 a, 241 a of the upper plate 141, 241. 

What is claimed is:
 1. A buckle comprising: a male member; and a female member to which the male member is to be inserted and engaged, wherein the male member includes a male member main body, a pair of leg parts protruding from the male member main body and being elastically deformable in a direction of coming close to or separating from each other, and engaging portions respectively provided in the leg parts and being engageable to the female member, wherein the female member includes: a female member main body having an upper plate, a lower plate, an insertion hole, which is formed between the upper plate and the lower plate and configured to insert the pair of leg parts of the male member therethrough, and engaged portions configured to be engaged with the engaging portions of the pair of leg parts; and a string attachment part connected to the female member main body in front of an insertion direction of the male member and having a string attachment hole to which a string-shaped member is to be inserted and engaged, wherein the pair of leg parts of the male member or the female member is provided with an operation portion configured to elastically deform the pair of leg parts to release engagement between the engaging portions and the engaged portions, wherein the string attachment part has at least a pair of vertical bars extending in the insertion direction of the male member and a horizontal bar connecting the pair of vertical bars, wherein the pair of vertical bars and the horizontal bar are located below an upper surface of the operation portion, wherein a coupling wall extending downwards from a front side of the upper plate and coupled to at least one of the lower plate and the string attachment part is provided, and wherein the operation portion is positioned at an outside in a width direction with respect to an outer edge of the coupling wall in the width direction at a state where engagement between the engaging portions and the engaged portions is released.
 2. The buckle according to claim 1, wherein the pair of vertical bars and the horizontal bar are located below a center of the operation portion in a thickness direction.
 3. The buckle according to claim 1, wherein the operation portion is positioned at an inner side in the width direction with respect to an outer edge of the string attachment part in the width direction at the state where the engagement between the engaging portions and the engaged portions is released.
 4. The buckle according to claim 1, wherein the string attachment part of the female member further has a pair of coupling bars extending in the width direction from the lower plate and coupled to the pair of vertical bars, respectively, and wherein the coupling wall gradually widens from the upper plate towards the coupling bars.
 5. The buckle according to claim 1, wherein the string attachment part of the female member further has a pair of coupling bars extending in the width direction from the lower plate and coupled to the pair of vertical bars, respectively, and wherein the coupling bars are located below a center of the operation portion in a thickness direction.
 6. The buckle according to claim 5, wherein when the engaging portions of the pair of leg parts are engaged to the engaged portions of the female member, leading end portions of the leg parts overlap with the coupling bars in the thickness direction.
 7. The buckle according to claim 1, wherein a lower surface of the string attachment part is formed below a lower surface of the lower plate, and wherein the lower surface of the lower plate has an inclined surface inclined downwardly towards the lower surface of the string attachment part.
 8. The buckle according to claim 1, wherein a lower surface of the string attachment part is formed below a lower surface of the lower plate, and wherein the lower surface of the string attachment part has an inclined surface inclined downwards and is coupled to the lower surface of the lower plate.
 9. The buckle according to claim 1, wherein the male member further has a string attachment part provided in the male member main body and having a string attachment hole to which a string-shaped member is to be inserted and engaged, and wherein when the male member is inserted and engaged to the female member, the pair of vertical bars and the horizontal bar of the female member are positioned on a line passing through the lower surface of the string attachment part of the male member and being parallel with insertion direction of the male member. 